Occurrence of Per and Polyfluoroalkyl Substances in Rural Wastewater Treatment Plants and Comparison to Large Treatments Plants

Authors

• Madeleine Rauhauser, University of Nebraska-LincolnFollow

First Advisor

Shannon Bartelt-Hunt

Date of this Version

12-2025

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Environmental Engineering

Under the supervision of Professor Shannon Bartelt-Hunt

Lincoln, Nebraska, December 2025

Comments

Copyright 2025, Madeleine Rauhauser. Used by permission

Abstract

Per and polyfluoroalkyl substances (PFAS) are a class of compounds defined by their carbon – fluorine bonds, which are incredibly strong. The strength of this bond makes these compounds very useful industrially, they are used as waterproof and grease proof coatings, and as fire retardants. The same thing that makes them useful industrially makes them incredibly recalcitrant in the environment, it is difficult to destroy these compounds. PFAS are also suspected to cause health impacts in people, such as kidney cancer and low birth weights. Wastewater has been commonly identified as a contributor to the amount of PFAS in the environment, though studies have focused on large treatment facilities and not those that serve small communities. PFASs widespread use and recalcitrance in the environment have made them omnipresent, making detection at environmentally relevant levels difficult. The first objective of this study sought to identify potential sources of contamination in our laboratory when adapting EPA method 1633 for use with small wastewater samples. The second objective of this study was to quantify PFAS in wastewater grab samples from communities serving fewer than 10,000 people in the state of Nebraska and to compare this data to larger treatment facilities.

Background contamination in the laboratory was found to be widespread at low levels, especially for perfluoro butyric acid (PFBA), its precursors, and 6:2 fluorotelomer sulfonic acid (6:2 FTS). Steps to reduce this contamination are established, but it is impossible to completely remove uncertainty from contamination in a typical laboratory. Wastewater effluent was found to contain between 10.21 and 580 ng/L of total PFAS, while finished biosolids contained 0.66 to 971 ng/g. On a flow rate and per population basis this is equivalent to the per capita load of PFAS generated by large municipal treatment facilities. Our findings indicate that small treatment facilities do have an impact on the widespread distribution of PFAS in the environment.

Advisor: Shannon Bartelt-Hunt